Authentication circuitry may be used in a device to ensure that authorized parts are used in systems to prevent damage to the systems. Example devices include inkjet cartridges and power cords for electronics. In some examples, a user may remove the authentication circuitry from a device and reuse the authentication circuitry on an unauthorized device.
For electronic devices, especially higher-end devices, authentication circuitry may be positioned on the device such that the authentication circuitry is not exposed and not easily detected by an end user. The authentication circuitry may be fully covered with additional material or with a case. In some examples, such as an inkjet cartridge, the input-output (IO) pads of the authentication circuitry may be exposed so that the IO pads may electrically connect to a printer through a socket when the cartridge is placed in the printer.